Waste disposal has in recent years focused to an ever greater extent on the recycling of wastes to produce usable materials. The recycling concept is being gradually realized through segregated disposal of waste and the like. However satisfactory results have not yet been obtained yet because of strict social and economic restrictions related to labor, facilities, cost and other factors related to the requirements for segregated disposal.
There is a growing demand for inhibiting, over the social life, human activities which result in deterioration of the global environment. An especially significant issue in connection with waste disposal is how to suppress the emission and dissipation of carbon dioxide, dioxins, nitrogen oxide (NOx), sulfur oxide (SOx), soot, heavy metal sand the like produced in the process of incinerating or otherwise treating waste. For example, carbon dioxide produced when carbon-containing wastes are incinerated is though to contribute to the greenhouse effect, and elaborate efforts are made in attempts to control their emission into the atmosphere. Incineration of chlorine-containing waste additionally produces a substance group having high toxicity which are generally collectively referred to as dioxins. Under the present circumstances, the emission into the air can be controlled for some extent by incinerating at an adequately high temperature, keeping a constant incineration temperature, using a reburning device, or the like, but further suppression of the emission of dioxins still remains as a problem to be solved.
Therefore, a near-future waste disposal system must be a system which can reproduce a large volume of useful resources from waste and be built and operated without involving much time and labor, large facilities, or high cost, and is environmentally friendly without producing or releasing carbon dioxide or dioxins. The system described in Japanese Patent No. 2651994, for example, is an example known system which can partly respond to such social demands. The disclosed system produces activated carbon from scrap tires by heating the scrap tires in a nitrogen atmosphere not containing oxygen. This system does not produce carbon dioxide because the scrap tires being heated are kept isolated from oxygen and metals such as steel wire and the like contained in the waste tires can be recovered in a non-degraded reusable state. The disclosed system is a related to the recycling of scrap tires, and does not release carbon dioxide or the like.
This patented system, however, has a furnace called a carbonization chamber or the like as its basic configuration unit, generally requires installation of many chambers or furnaces including a plurality of carbonization chambers and their incidental reserve chambers or the like, and these chambers or furnaces must be provided in a sealable configuration which avoids all contact with the air. Therefore, it is facility scale (dimensions and weight), operation costs (power and thermal power costs and labor costs), and the like are all disadvantageously great.
Such a system can produce activated carbon by treating waste, but requires that the waste be treated in an oxygen-free state so as to change the activated carbon into inert carbon in order to obtain inert carbon. The inert carbon (e.g., bincho charcoal) has substantially no pores and a high carbon density and provides a high volume of far infrared ray radiated from carbon elements as compared with activated carbon having many pores and a low carbon density. Thus, the inert carbon is useful for applications employing far infrared radiation (e.g., a method of using it as the content of an infrared pillow, a method of using it as the contents of infrared concrete, etc.). The inert carbon is also useful because carbon nanotubes and the like can be produced by activating the inert carbon. Accordingly, there is great demand for a system which can mass-produce inert carbon by directly obtaining the inert carbon.